764 



According to m}^ definition of this association, it may perhaps 

 partly agree with the Ulvaceenformation described by Simmons 

 (p. 251). He at least says so himself (66, p. 174); but it seems to 

 me, that his formation agrees mostly with the Monostroma-Entero- 

 Tnorp/ia- association mentioned below. Simmons declares, how- 

 ever, that his formation belongs to the Httoral region, though he 

 remarks that it may be found as far down as about 2 meters 

 below ebb mark. Referring here to my statement on p. 710 I need 

 only mention, that it seems very unnatural to call a vegetation Ht- 

 toral, when it is found below the lowest water mark in a locality 

 subject to ebb and tide, and on the whole below the littoral algæ- 

 vegetation, even though most of these algæ may also be found in 

 the littoral region. 



According to the descriptions of the algæ-associations on the 

 coasts of Norway, I think, that this association shows no small 

 similarity to the Dictijosiphon-, Spermatochnus- and Cora////?a-forma- 

 tions, described by Boye. 



The Monostroma-Enteromorpha-Association. 



This association reaches from the surface of the sea down to a 

 depth of a few fathoms. The transition from the previously men- 

 tioned association is often smooth, as the Chiorophyceæ under cer- 

 tain conditions gradually become predominant. The association is 

 especially luxuriant in the bottom of the fjords, where the outflow 

 of the rivers turns the water more or less brackish. It mostly grows 

 on a bottom of stones or gravel in shallow water, but it may also 

 be found drifting on the surface of the sea. 



Among the species characteristic of this association Monostroma 

 fuscum ought to be mentioned, as it is often predominant and may 

 be found as a pure facies covering large spaces of the bottom. Usu- 

 ally, various species of Enteromorpha , especially ^. clathrata and 

 forms of E. intestinalis, åre, however, intermingled. The latter species 

 may grow in the fresbest water, especially var. genuina and var. 

 proUfera which often form large entangled masses at the mouths 

 of rivers, for instance in Kalbakbotn. 



Further, varieties of Monostroma undiilatum are found in the 

 association. In Klaksvig, in the direct vicinity of the land, great 

 numbers of Chætomorpha tortuosa and an Acrosiphonia spec. are 

 found, besides the above-mentioned algæ. 



